1. Field of the Invention
The present invention relates to an improvement in an integrated fluid coking and coke gasification process for the production of unsaturated light hydrocarbons and aromatics useful as chemicals and chemical intermediates.
2. Description of the Prior Art
The fluid coking process for the production of fuels, such as gas oil and naphtha is a well known process and is disclosed in U.S. Pat. No. 2,881,130, the teachings of which are hereby incorporated by reference. Integrated fluid coking and coke gasification processes are also known and disclosed, for example, in U.S. Pat. Nos. 3,661,543 and 3,816,084, the teachings of which are hereby incorporated by reference.
Fluid coking processes for the production of chemicals and chemical intermediates are also known. See, for example, U.S. Pat. No. 2,846,360 and U.S. Pat. No. 2,871,183. Generally, when it is desired to produce chemicals rather than fuel oils, heretofore, the fluid coking process usually included a high temperature transferline coking zone and a fluidized bed coking zone.
It is also known to introduce a small amount of hot solids into a gas-solids separation zone, such as the cyclone separator, used to separate entrained solids from the vaporous coker product so as to prevent coke deposition on the walls of the cyclone separator. See, for example, U.S. Pat. Nos. 2,763,601; 2,859,168 and 2,943,993.
It has now been found that coking for the production of chemicals and chemical intermediates can be performed by coking a carbonaceous material in a conventional fluid coking zone and subsequently heating the resulting vaporous product to a temperature sufficient to crack the coker vaporous product to unsaturated hydrocarbons in a conventional gas-solids separation zone used to remove entrained solids from the coker vaporous product. The heat in the gas-solids separation zone is provided by passing a portion of hot solids from a gasification zone to the gas-solids separation zone.